Development of an Emulation-simulation Thermal Control Model for Space Station Application

Analysis techniques to evaluate the effects of changing thermal loads and the methods utilized to control temperature distributions in the orbital space station are essential. Analysis techniques including a user-friendly computer program, were developed which should prove useful in thermal design and system analysis of the the space station. The program uses a data base and user input to compute costs, sizes, and power requirements for individual components and complete systems. User input consists of selecting mission parameters, selecting thermal acquisition configurations, transport systems and distances, and thermal rejection configurations

Modeling of transient heat pipe operation

The overall goal is to gain a better understanding of the transient behavior of heat pipes operating under both normal and adverse conditions. Normal operation refers to cases where the capillary structure remains fully wetted. Adverse operation occurs when drying, re-wetting, choking, noncontinuum flow, freezing, thawing etc., occur within the heat pipe. The work was redirected towards developing the capability to predict operational behavior of liquid metal heat pipes used for cooling aerodynamic structures. Of particular interest is the startup of such heat pipes from an initially frozen state such as might occur during re-entry of a space vehicle into the Earth's atmosphere or during flight of hypersonic aircraft

Modeling of Transient Heat Pipe Operation

The major goal of this project is to develop mathematical models of heat pipes which can be used to predict transient behavior under normal and adverse conditions. The models and solution techniques are to be formulated so that they can be incorporated into existing NASA structural design codes. The major parameters of interest are heat flux distribution, temperature distribution, working fluid pressure distribution, fluid and containment thermal and mechanical properties and geometry. Normal transient operation is taken to be operating conditions where the capillary structure remains fully wetted. Adverse transient operation occurs when drying, re-wetting, choking, non-continuum flow, thawing, freezing, etc., occur in the internal heat pipe working fluid

Modeling of transient heat pipe operations

An analysis of the steady, compressible, one-dimensional, laminar flow of sodium vapor is presented for a case of a flat plate-type heat pipe with asymmetrical boundary conditions. In addition, shear stress at the liquid-vapor interface, variations of vapor quality, and momentum and energy factors are considered. A similarity solution for a semiporous channel is used to provide the velocity profile at cross sections

Development of an emulation-simulation thermal control model for space station application

Many features were added to the Thermal Control System (TCS) program to increase its user-friendliness. Several apparent inconsistencies were identified. In some instances, these have led to modifications to the source programs. With the summary line-sizing information, the user can more readily compare the TCS program results with other available data. Two mathematical models were completed: one deals with sizing and analysis of bus heat exchangers and the other provides a means of analyzing a variety of heat pipe radiator designs. A generic heat pipe model was added to the TCS Analysis Program

Development of an emulation-simulation thermal control model for space station application

The goal of this program is to develop an improved capability for comparing various techniques for thermal management in the space station. The work involves three major tasks: Develop a Technology Options Data Base (Task 1); Complete Development of a Space Station Thermal Control Technology Assessment Program (Task 2); and Develop and Evaluate Emulation Models (Task 3)

TWO NEW SPECIES OF ACRONYCHIA (RUTACEAE) FROM NEW GUINEA

Two new species of Acronychia from New Guinea,. glauca Hartley and A. loisseliana Hartley, are described and illustrated

Moving Forward 21st Century Pathways to Strengthen the Ocean Science Workforce Through Graduate Education and Professional Development

The scope of emerging national and international ocean-related issues facing society demands that we develop broad perspectives on graduate education and training in the ocean sciences. A multifaceted ocean workforce and new kinds of intellectual partnerships are needed to address ocean science research priorities, strengthen our understanding of coupled human-natural ocean systems, engage and inform public policy and management decision making, and increase ocean literacy. Alumni from graduate programs in ocean sciences are following diverse career paths in academia, government, nongovernmental organizations, and industry, and thus can inform us about the diverse skills needed to succeed. The ocean science academic community should build on its current strengths (e.g., multidisciplinary and multi-institutional research and education, international partnerships), and capitalize on what some might view as limitations (e.g., remote, yet inviting, coastal campuses, diversity of ocean science programs), to become an incubator of innovation that will advance the field and strengthen graduate education and training. Partnerships within and among institutions with ocean-related programs, and with professional societies, employers, and others, can help us provide cutting-edge, relevant academic options, facilitate professional development, and proactively position graduates for career paths that reflect and address important societal needs

Nature versus Nurture: The curved spine of the galaxy cluster X-ray luminosity -- temperature relation

The physical processes that define the spine of the galaxy cluster X-ray luminosity -- temperature (L-T) relation are investigated using a large hydrodynamical simulation of the Universe. This simulation models the same volume and phases as the Millennium Simulation and has a linear extent of 500 h^{-1} Mpc. We demonstrate that mergers typically boost a cluster along but also slightly below the L-T relation. Due to this boost we expect that all of the very brightest clusters will be near the peak of a merger. Objects from near the top of the L-T relation tend to have assembled much of their mass earlier than an average halo of similar final mass. Conversely, objects from the bottom of the relation are often experiencing an ongoing or recent merger.Comment: 8 pages, 7 figures, submitted to MNRA

Scholarly communication in transition: The use of question marks in the titles of scientific articles in medicine, life sciences and physics 1966–2005

The titles of scientific articles have a special significance. We examined nearly 20 million scientific articles and recorded the development of articles with a question mark at the end of their titles over the last 40 years. Our study was confined to the disciplines of physics, life sciences and medicine, where we found a significant increase from 50% to more than 200% in the number of articles with question-mark titles. We looked at the principle functions and structure of the titles of scientific papers, and we assume that marketing aspects are one of the decisive factors behind the growing usage of question-mark titles in scientific articles